Tack machine



June 21, 1932. G. B. BAKER ET AL TACK MACHINE Filed Oct. 24, 1927 2Sheets-Sheet l I. .l T

TACK MACHINE Filed Oct'. 24. 1927 2 Sheets-Sheet 2 i 22 0/2 .14 01 T i47 f la; id

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Patented June 21, 1932 UNITED STATE S PATENT OFFICE GEORGE IB. BAKER,HERBERT B. BAKER, AND EDWARD C. BAKER, OF BROCKTON, MAS- SACHUSETTS,ASSIGNORS, BY MESNE ASSIGNMENTS, .IIIO GEORGE -B. BAKER AND EDWARD C.BAKER,-OF BROCKTON,.MASSACHUSETTS, AS SURVIVING JOINT TENANTS I TACKMACHINE Application filed October 24, 1927. Serial No. 228,138.

This invention pertains to tack and nail making machines and relatesmore particularly to means for feeding the blanks or tack strips to thecutting instrumentalities. In our Patent No. 1,555,933 dated October 6,.1925, we have disclosed a tack machine of highlv eflicient and usefulcharacter, which, in common with other known types-of tack machinesemplovs intermittently actuated feed rolls for advancing the blanks orStack strips toward the cutting instrumentalities. Such an arrangementof feed rolls, particularly when used in the Specific environmentdisclosed in our aforesaid patent, constitutes veryeflective anddesirable means for feeding the blanks, since the use of such rollsmakes it possible to avoid the complications attendant upon endwisereciprocation of the blank holding barrel (as is common in certain typesof machines) while as disclosed in our aforesaid patent, such rolls alsoperform the function of detector means in a verysatisfactorv way.

It has been the common practice to :turn such feed'rolls in the forwardor work advancing direction by positive means, for example,

a cam, eccentric. or crank which moves the rolls a fixed andpredetermined distance at each successive actuat1on,'prov1s1on somet mesbeingmade for adiusting this distance.

While this type of mechanism, when accurately adiusted. should produce(intheorv at least) substantially perfect results, it does notaccurately accommodate itself to slight changes in conditions ofoperation and does not always attain the theoretical perfection ofoperation which might be expected. Thus slight variations in thematerial operated upon or in the operation of the various moving partsof the machine are sufficient to interfere with the "accuracy of thefeed, it being noted that in the formation of tacks of small size thefeed movement is of the order of a few hundredths of an inch.

In accordance with our present invention we avoid the above difiicultiesand eliminate substantially allimperfect work arising from the abovecauses, although retaining the feed rolls with their advantages, but soactuate these rolls as toqcause the blank to be crowdi ed forward withsubstantially continuous pressure toward the cutting position justbefore and during the entire cutting operation. This crowdingforward ofthe blank is not dependent upon the action of a reciprocating part ofuniform'throw, but is substantially c tinuous, except when the barrel isturning or oscillating, and jams the forward end of the blank forciblyagainstthe usual limiting stop so that as the cutters are actuated theyi "vention which is illustrated by wayof example in the accompanyingdrawings in which: Fig. 1 is aside elevation of a tack machine of thetvpe above referred to and having the present improvements appliedthereto;

Fig; 2 is a fragmentary side elevation, to larger scale, partly insection, showing the forward portion of the blank supportingbar- :reland associated parts,

F ig. -3 is a fragmentary plan view, partly. in section on the line 33of Fig. 2; F ig. 4 is a fragmentary verticalsection on the line 4 4 ofFig. 3; and

Fig. 5 is a vertical section on the of Fig. l. c 5 Referring to thedrawings thenumeral 1 indicates the supporting frame of a tack machineof the type referred to. This frame is provided with bearings for themain shaft having the hand wheel 2 and carrying the usual cams, cranks,and other devices for actuating the operating parts of the machine,including the movable cutters 5 and 6 (Fig. 2) and the movable limitingstop 7... The frame 1 also supports an anvil block 3 carrying the fixedor ledger blade 4, the latter being provided with a diagonal cuttingedge in the usual manner. Resilient guards or. guides 9 are supportedupon the'anvil block 3 by means of brackets 11, these guards cooperating in usual manner to position the blank line 5- 5 laterally as itis advanced toward the cutters.

20 carried by a block 21 which is carried by the table 12. A cross bar22 is secured to the upper ends of the posts 19 and constitutes anabutment for a spring (not shown) whose lower end engages a yoke member27 bearing upon the upper surface of the barrel 14.'

This spring tends to hold the barrel downwardly with its free lowerextremity engaging the upper surface of the anvil block but permits thebarrel to rise slightly as it is oscillated during the operation of themachine.

Straps 28 and 29 constitute the means for oscillating the barrel as isusual in machines of'this type. These straps are wound in oppositedirections about the barrel, and their lower ends are secured tooppositely directed arms of a lever 30 fulcrumed upon the extension 13.This lever is rocked at suitable intervals by means of a link 32actuated by a cam or crank carried by the main shaft of the machine.

A yoke 38 is secured to the bracket 17 and supports an elongatedguideway 39 forming a part of the automatic replenishing means which isfully described in our aforesaid patent and which forms no essentialpart of the present invention.

Near its lower end the barrel is furnished with an extension or sleeve40 (Fig. 2) which carries a box-like casing 40 which is preferably openat its top and bottom and which has a passage aligning with the passagethrough the main part of the barrel. The

casing 40 is provided with journal openings for a transverse shaft 41upon which is mounted a knurled feed roll 42 which cooperates with afeed roll 43 mounted upon a second transverse shaft 44. Preferably theupper shaft 41 is journaled in movable bearings and is pressed towardthe other shaft by means of a spring or springs'as more fully disclosedin our aforesaid patent. Also there is preferably associated with theupper shaft or its bearings a movable electrical contact 80 adapted toengage an insulated contact ring 80 mounted on the barrel, all asfullydescribed in our patent above referred to.

The shafts 41 and 44 are provided with intermeshing gear wheels 45 and46 which constrain the shafts to move at substantially the same speed inopposite directions. One of these shafts, as here shown the shaft 41, isprovided at one end with a ratchet wheel whichactuates the feed rolls.

47 fixedly secured to the shaft and constituting means for driving thefeed wheels. A driving pawl 48 (Fig. 4) engages the teeth of thisratchet wheel, being pressed into engagement with such teeth by means ofa sprmg 52. i This pawl 48 is pivotally supported upon a pawl carrier 49which slides longitudinally in suitable guides 50 and 51 projecting fromthe side of the casing 40 A spring 53, connected with the pawl carrier,tends to move the latter to the left as viewed in Figs. 2, 3 and 4 thatis to say, in a direction such as to retract the pawl and cause it toengage a fresh tooth of the ratchet wheel. Preferably the pawl carrier49 is of angular section or othersuitable shape to prevent it fromturning in its bearings and is provided at its rear end with ananti-friction roller 54.

The block 21 is furnished with a journal opening for 'a transverse shaft55 constituting the axle of an actuator lever having the downwardlyextending arm 56. A tension spring 57 is secured to the lower end of thearm 56 and to a fixed pin 58- conveniently mounted upon the extensionmember 13.

The actuator lever also comprises a pair of upwardly extending pusherarms 59 and 60 disposed'respectively at opposite sides of the barrel 14and so positioned that during the cutting operation one or the'other ofthese arms engages the anti-friction roll 54 of the pawl carrier. Thearms 59 and 60 are substantially'upright and if desired their upper endsmay be bent slightly as" indicated at 60 although this is not essential.The actuator lever also has an upwardly extending arm 61 which ispivotally connected at its upper end to a link 62 extending to a member63 which is rocked by a cam or other suitable element carried by themain shaft.

i The forward end of the casing 40 supports a bracket 64 carrying thenose piece comprising the spaced upper and lower members 65 and 66constituting the means for guiding the blank B near the cutting point.

The electrical contact elements 83 and 86 shown in our aforesaid patentare in this instance moved to the left of the bracket 20 as viewed inFig. 1 to avoid interference with the feed roll actuating meansdescribed, but

such contacts function in the same way as described in our patent.

The operation of the machine is in general similar to that of tackmachines of this type and more specifically as described in ouraforesaidpatent except for the mechanism As indicated in Fig. 2 the parts are inposition for the downward movement of the cutters 5 and 6. -At this timethe forward end of the blank B ment with the roll 54 of the pawl carrierby the action of the spring 57. This spring is long and strong and tendsto exert a constant pressure upon the pawl carrier, urging the latter ina forward direction or to the right,

as Viewed in Fig. '2, thus tending to turn the V ratchet wheel 47through an arc of large extent. If free to do .so the ratchet wheelwould turn and with it the feed rolls to an extent much greater thannecessary to advance the blank B the proper distance for cutting, but

tially constant pressure, against the stop.'

By reason of this normally exerted force the blank is held firmly inproper position durmg cutting.

As the barrel 14: must be oscillated through 180 between successivecutting operations,

and as the pawl carrier turns bodily with the barrel, the roll 54 movesout of engagement with the arm 60 as the barrel starts to oscillate. Assoon as the roll 54 disengages the arm 60, the spring 53 is free toretract the pawl carrier so that the pawl may engage a fresh tooth ofthe ratchet wheel. This rearward movement of the pawl carrier, as wellas such forward movement of the actuator lever as may be permitted afterthe pawl carrier has disengaged the arm 60, so positions the parts thatas the pawl carrier approaches the dotted line position indicated at 54'in Fig. 3, it would normally contact with the end of the arm 59 of theactuator lever. To avoid such contact we have provided the lever withthe arm 61 and the actuating link 62, and as the barrel nears thecompletion of its oscillation, the arm 61 is rocked so as to swing theactuator lever and move the arms 60 and 59 to the dotted line positionshown in Fig. 2. In this position the roll 54 is free to'swing down intoits lowermost position, whereupon the arm 61 is permitted to rockbackwardly, causing the arm 59. to engage the :roll, thus reapplyingpressure to the pawl carrier and feeding the blank forwardly withsubstantially a constantly maintained force against the limiting stop.

The above operations are repeated at each successive oscillation of thebarrel, and it is evident that, except during the time when the barrelis turning, the action of the spring 57 through the intervening parts isto press the blank forwardly with substantially constant force prior toand during the entire cutting operation. All back-lash between the blankand the cutting instrumentalities is thus avoided, and since theoperative movement of the actuator lever is not dependent upon anyreciprocating element having a definite length of throw, the mechanismiscapable, withoutadjustment, of feed- ,tending to move the ing the blankto "the proper extent .and without reference to the size .of the pieceto be removed from the end of the blank.

By the provision of the mechanism above described we have been able toeliminate sub- 1 stantially all waste due to improper feedingand toobtain in many casesperfect, that is to say 100%, production. While wehave shown .a preferred embodiment of our invention, we contemplatethatisimilar result-s may be obtained by mechanism of somewhat differentcharacter but operating upon the same general principle, and we wish itto be under- :stood that it is\within the scope of our invention to makesuch changes in proportion and relative arrangement of parts and tosubstitute such equivalents as fall Within the scope of the appendedclaims.

We claim:

1. A tack machine means for supporting a blank, intermittently actingfeed rolls for advancing the blank step bystep, cutting means, :and stopmeans for lim1ting advance of the blank, said machine comprising meanstending to turn the feed rollsintermittently through successive arcseach in excess of the. amount necessary to engagethe end .of-the'blankwith the stop means.

. 2. A tack machine of the type having means for supportin a blank, feedrolls for advancing the blani, cutting means, and stop means forlimiting advance of the blank, said machine comprising means normallyexlelrting yielding force for turning thefeed ro' s.

3. A tack machine of the type having means for supporting a blank, feedrolls for advancing the blank, cutting means, and'stop means forlimiting advance of theblank,said machine comprising spring-meansnormally exerting force for turning the feed rolls to advance the blankinto engagement with the stop means.

4. A tack machine of the type having means for supporting a blank, feedrolls for advancing the blank, cuttingmeans, and stop means for limitingadvance of the blank, said machine comprising spring means nor mallytending to turn the feed rolls an amount in excess of that'necessary toengage the blank with the stop means. i

5. A tack machine of the type having means for supporting a blank, feedrolls for advancing the blank, cuttingmeans, and stop means for limitingadvance of theblank, said machine comprising a pawl and ratchet. forturning the'feed rolls, and a spring normally pawl and thereby to turnthe feed rolls. i s V 6. A tack machine having. in combination with anoscillating and non-reciprocating prising blank advancing means disposednear:

of the type having the delivery end of the barrel, said feed devicenormally exerting resilient pressure while the barrel is stationary toadvance a blank along the barrel'into engagement with the stop means andbeing adapted to advance a blank of unlimited length.

7. A tack machine having a combination with an oscillating andnon-reciprocating tubular blank supporting barrel into one end of whichthe blank is introduced and from the other end which the blank is dewithan oscillating and non-reciprocating,

tubular blank supporting barrel, cutting means, stop means, and feedrolls adjacent to the delivery endv of the barrel normally exerting acontinuous force during intervals between successive oscillations of thebarrel causing-the end of the blank to press forcibly against the stopmeans.

9. A tack machine of the type having an intermittently oscillatingtubular blank supportingbarrel, feed rolls for advancing a blank alongthe barrel, cutting means, and stop-means for limiting the advance oftheblank, said machine comprising means normally exerting yielding forcewhile the barrel is stationary tending to turn the feed rolls, saidforce exerting means being inoperative during a part at least of theoscillatory movement of the barrel.

10. A tack machine of the type having an intermittently oscillatingblank supportlng barrel, feed rolls for advancing a blank along thebarrel, cutting means and stop means for limiting advance of the blank,said machine comprising spring means normally tending to turn the feedrolls, said spring means being inoperative during a part at least of theoscillatory'movement of the barrel.

11. A tack machine of the type having an intermittently oscillatingblank supporting barrel, feed rolls for advancing a blank along thebarrel, cutting means, and stop means for limiting advance of theblank,said machine comprising a ratchet wheel connected to one of the feedrolls, a pawl for driving the ratchet, and an actuator for the pawlnormally exerting continuous force, during intervals between successiveoscillations of the barrel, in a direction to move the pawl for turningthe ratchet. a

12. A tack'machine of the type having an intermittently oscillatingblank supporting barrel, feed rolls for advancing a blank along thebarrel,cutting means, and stop means for limiting advance of the blank,said machine comprising a ratchet and a ratchet-driving pawl for turningthe feed rolls, and an actuator for the driving pawl normally exertingcontinuous force while the barrel is stationary in a direction foroperatively moving the pawl, said actuator being inoperative during apart at least of the oscillating movement of the barrel.

13. A tack machine of the type having an intermittently oscillatingblank supporting barrel, feed rolls for advancing a blank along thebarrel, cutting means, and stop means for limiting advance of the blank,said machine comprising a ratchet and a ratchet-driving pawl for turningthe feed rolls, a movable carrier for the pawl, an actuator normallyengaging said pawl carrier and tending to move the latter so as to turnthe ratchet wheel, and means for disengaging the actuator from the pawlcarrier as the barrel oscillates.

14;. A tack machine of the type having an intermittently oscillatingblank supporting barrel, feed rolls for advancing a blank along thebarrel, cutting means, and stop means for limiting advance of the blank,said machine comprising pawl and ratchet means for turning the feedrolls including a movable pawlcarrier, spring means for retracting thepawl carrier to enable the pawl to engage a new tooth of the ratchet, aspring operated actuator lever normally engaging the pawl carrier andurging it forward thereby to turn the feed rolls, and means moving intimed relation to the barrel for swinging said actuator lever out ofengagement with the pawl carrier as the barrel oscillates.

15. A tack machine of the type having an intermittently oscillatingblank supporting barrel, feed rolls for advancing a blank along thebarrel, cutting means, and stop means for limiting advance of the blank,said machine comprising pawl and ratchet means for turning the feedrolls including a movable pawl carrier, spring means for retracting thepawl carrier to enable the pawl to engage a new tooth of the ratchet, anactuator comprising members disposed upon opposite sides of the barrelrespectively and adapted alternately to engage the pawl carrier, meanscausing that one of the actuator members which at any time engages thepawl carrier to urge the latter forward in ratchet driving direction,and means for withdrawing the actuator member's from operativepositionas the barrel oscillates.

16. A tack machine of the type having means for supporting a blank,r'eed rolls for advancing the blank, cutting means, and stop means forlimiting advance of the blank, said machine comprising pawl and ratchetmeans for turning the feed rolls including a movable pawl carrier,spring means for retracting the pawl carrier to enable the pawl toengage a new tooth of the ratchet, an actuator normally urging the pawlcarrier in the opposite direction, and means for intermittentlyseparating the actuator from the pawl carrier, thereby permitting saidspring means to retract the carrier.

17. A tack machine of the type having an intermittently oscillatingblank supporting barrel, and feed rolls for advancing a blank along thebarrel,the rolls moving bodily with the barrel, said machine comprisingpawl and ratchet means for advancing the feed rolls, said pawl andratchet means including a movable pawl carrier, an actuator levercomprising a pair of arms disposed respectively at opposite sides of thebarrel and adapted alternately to engage the pawl carrier, spring meansurging the actuator lever in such a direction as to cause that one ofits arms which engages the pawl carrier to press against the latter, andcam actuated means for swinging said arms out of operative position asthe barrel oscillates.

Signed by us at Boston, Massachusetts, this 18th day of October, 1927.

GEORGE E. BAKER. HERBERT B. BAKER. EDWARD C. BAKER.

